This invention relates to treatment of articles using sterilizing compositions. More particularly, this invention relates to the use of chemical sterilants for sterilization of articles.
Articles used in biological and/or medical procedures are sterilized to significantly reduce or eliminate the number of potentially contaminating microbes associated with the biocompatible articles. Contaminating microbes associated with articles can lead to failure of biological and/or medical procedures. In particular, microbial contamination in medical procedures can lead to serious health risks.
A variety of biocompatible medical articles are designed particularly for contact with a patient""s bodily fluids. The duration of this contact may be relatively short, as is typical with wound dressings, or may be long term, as is typical with prosthetic heart valves implanted into the body of a recipient. Some articles such as catheters can have either short term or relatively long term contact. Other articles typically having relatively short term contact with the patient include, without limitation, burn dressings, contact lenses and surgical instruments. Other articles typically having long term contact with a patient include, without limitation, prostheses.
Contact of articles with bodily fluids creates a risk of infection. This risk can be very serious and even life threatening. In addition, considerable costs, and longer or additional hospital stays, may result due to infection. For example, infections associated with dressings can increase the seriousness of the injury for burn victims. Also, infection associated with an implanted prosthesis can necessitate replacement of the device. Thus, there is a need for sterility assurance in these articles.
Infections are a particularly common complication resulting from the use in hospitals of percutaneous devices such as catheters. Infections related to catheter use can result from intracutaneous invasion during catheter insertion or from invasion by way of the exit site during use. Adherence of bacteria to the catheter surface complicates treatment of the infection.
Prostheses, i.e., prosthetic articles, are used to repair or replace damaged or diseased organs, tissues and other structures in humans and animals. Prostheses generally must be biocompatible since they are typically implanted for extended periods of time. Examples of prostheses include, without limitation, prosthetic hearts, prosthetic heart valves, ligament repair materials, vessel repair and replacement materials, and surgical patches. Many prostheses incorporate tissue as at least a component of the prosthesis.
Physicians use a variety of prostheses to correct problems associated with the cardiovascular system, especially the heart. For example, the ability to replace or repair diseased heart valves with prosthetic devices has provided surgeons with a method of treating heart valve deficiencies due to disease and congenital defects. A typical procedure involves removal of the native valve and surgical replacement with a mechanical or bioprosthetic valve. Another technique uses an annuloplasty ring to provide structural support to the natural annulus of the valve.
Prosthetic Valve Endocarditis (PVE) is an infection that can be associated with a heart valve prosthesis. Bacteria can form colonies at the surgical site associated with the implant and in the fabric of the sewing cuff of the valve prosthesis. The growth of tissue into the sewing cuff material also is associated with the attachment of bacteria and other pathogens. For this reason, heart valve recipients are cautioned regarding activities that may introduce bacteria into the bloodstream, such as dental work. For tissue replacement valves, PVE more commonly is associated with the leaflet portion of the valve rather than the sewing cuff portion of the valve.
PVE can be caused by gram-negative bacteria, gram-positive bacteria, fungi or rickettsia. PVE caused by gram-positive bacteria is particularly prevalent. Diagnosis is based generally on two positive blood cultures for the same organism along with clinical symptoms. Certain organisms are difficult to culture, however, which can complicate diagnosis.
With respect to replacement heart valves, care must be taken to ensure sterility during production and to prevent contamination during the replacement valve implantation process. For example, some tissue heart valves are stored in sterilizing solutions. In addition, to ensure sterility or to reduce perioperative contamination, some surgeons apply antibiotics to the prosthesis prior to implantation.
Articles used in in vitro and in vivo biological procedures may also require sterilization. Contamination of the articles used in biological procedures with undesirable microbes can result in erroneous results. Microbial contamination of culture flasks, for example, can lead to proliferation of microbes and inhibition of the desired cell cultures.
Analysis of biological samples, for example, can be conducted using optical methods such as absorption or transmittance of light. Assays using optical methods can determine the quantity of cells in a sample. The presence of contaminating microbes in a cell culture, however, can lead to erroneous data regarding the number of cells present in a sample. This can lead to experimental setbacks of days, months and sometimes even years, especially if the microbial contamination is not detected early.
In a first aspect, the invention pertains to a method of treating an article. The method includes contacting the article with a sterilizing composition. The sterilizing composition includes an epoxy amine compound and an alcohol.
In a further aspect, the invention pertains to a method of treating an article including cross-linked tissue. The method includes contacting the article with a sterilizing composition that includes an epoxy amine compound. The cross-linked tissue generally has been further processed prior to contact with sterilizing composition.
In another aspect, the invention pertains to a method of treating a non-proteinaceous article. The method includes contacting the article with a sterilizing composition that includes an epoxy amine compound.
In a further aspect, the invention pertains to a sterilizing composition including an epoxy amine compound and an alcohol.